1. Field of the Invention
The present invention relates to apparatus and methods for removing fat from the external surface of an internal organ, and more specifically to apparatus and methods for selectively removing all or part of the fatty layer on the epicardial surface of a mammalian patient.
2. Brief Description of the Related Art
Recent advances in cardiology, radiology, and cardiothorasic surgery have allowed patients suffering from various diseases of the internal organs to benefit from less invasive techniques to surgically treat their conditions. With the advent of newer techniques, however, come newer difficulties in the application of these techniques to all the qualified patients.
Recent advanced techniques and devices allow for the correction of numerous defects of the internal organs, e.g., the heart, by access to the surface of the organs. For example, performing coronary artery bypass surgery on a beating heart has been used to treat coronary artery disease, attaching leads to the exterior surface of the heart to collect diagnostic data and to pace the heart, or performing atrial fibrillation procedures. In all of these procedures, however, often a thick layer of fatty tissue must be removed from around the heart to expose the myocardial tissue to be treated. To further complicate the procedure, the fatty layer may be enveloped in a tougher layer of connective tissue, the epicardium, which must first be incised to expose the fat underneath. Furthermore, the vasculature which provide blood to the heart itself, the coronary arteries and veins, may be located on the exterior of the cardiac tissue and under and in the fat. The coronary arteries and cardiac veins traverse the myocardial surface, supplying oxygenated blood and conducting deoxygenated blood away from the cardiac tissues, respectively. Typically, the epicardium is cut with a scalpel to expose the fat underneath, which in turn is incised with a scalpel to expose the surface of the heart to perform a procedure, e.g., bypass surgery, pacing lead attachment, atrial fibrillation procedures, etc. The use of a scalpel to remove the fat clearly presents a level of danger to the patient""s coronary arteries which is only marginally tolerable; the consequences of mishap are severe.
The fat layer is generally a semi liquid form at body temperature. At elevated temperatures the fatty tissue will become more liquified. The cell membranes of the fat tissue can be ruptured when they are mechanically stressed, which will allow the fat contents of the cell to flow freely.
Prior devices exist which aspirate fat or other substances from the body of a patient, but which are not suitable for removing the fat layer from the external surface of an internal body organ. Laparoscopes exist, but are not useful because they cannot break up fatty tissue while ensuring that larger blood vessels which are located under the fat are not also severed. Numerous atherectomy devices have been proposed, however they are far too small to be effectively employed to remove the sometimes large volumes of fat which covers the organ, and also do not provide any protection for the underlying blood vessels.
In accordance with a first exemplary embodiment of the present invention, a fat removing device comprises a cannula having a longitudinal axis, a proximal end, a distal end, a lumen extending proximally along said longitudinal axis, and an opening in said cannula at said distal end which fluidly communicates said lumen with the exterior of said cannula, and a protective mesh attached to said distal end and distal of said opening, said mesh including openings sized to permit human fat cells to extrude through said openings when said mesh is pressed against a mass of human fatty tissue, said openings also sized to prevent a human blood vessel which underlies said human fatty tissue from passing through said openings when said mesh is pressed against said mass of human fatty tissue.
In accordance with a second exemplary embodiment of the present invention, a fat removing device comprises a cannula having a longitudinal axis, a proximal end, a distal end, a lumen extending proximally along said longitudinal axis, and an opening in said cannula at said distal end which fluidly communicates said lumen with the exterior of said cannula, and an energy transmitting wire located in said cannula and including a tip distal of said cannula distal end, said wire and tip being longitudinally movable at a frequency and magnitude which at least partially disrupts the cell walls of said human fat cells.
In accordance with a third exemplary embodiment of the present invention, a fat removing device comprises a cannula having a longitudinal axis, a proximal end, a distal end, an outer diameter R, a lumen extending proximally along said longitudinal axis, and an opening in said cannula at said distal end which fluidly communicates said lumen with the exterior of said cannula, and a cutting element in said lumen adjacent said cannula distal end, said cutting element spaced from said cannula distal end a distance D, wherein R and D are together selected to permit human fat cells to extrude into said cannula opening when said cannula distal end is pressed against a mass of human fatty tissue, R and D are together selected also being sized to prevent a human blood vessel which underlies said human fatty tissue from passing into said cannula opening when said cannula distal end is pressed against said mass of human fatty tissue.
In accordance with a fourth exemplary embodiment of the present invention, a fat removing device comprises a cannula having a longitudinal axis, a proximal end, a distal end, a tip at said distal end, a lumen extending proximally along said longitudinal axis, and an opening in said cannula at said distal end which fluidly communicates said lumen with the exterior of said cannula, said cannula tip being angled inward, and a cutting element in said lumen adjacent said cannula distal end, wherein said cannula tip angle is selected to permit human fat cells to extrude into said cannula opening when said cannula distal end is pressed against a mass of human fatty tissue, said cannula tip angle also being selected to prevent a human blood vessel which underlies said human fatty tissue from passing into said cannula opening when said cannula distal end is pressed against said mass of human fatty tissue.
In accordance with a fifth exemplary embodiment of the present invention, a fat removing device comprises a cannula having a longitudinal axis, a proximal end, a distal end, a closed tip at said distal end, a lumen extending proximally along said longitudinal axis, and an opening in said cannula proximal of said distal end which fluidly communicates said lumen with the exterior of said cannula, a rotatable shaft in said cannula, a blade attached to said rotatable shaft adjacent said opening, wherein when said cannula opening is pressed against a mass of human fatty tissue, and when said rotatable shaft is caused to rotate, said blade rotates and cuts fatty tissue which has extruded through said opening, said cannula opening being sized to prevent a human blood vessel which underlies said human fatty tissue from passing into said cannula opening when pressed against said mass of human fatty tissue.
In accordance with a sixth exemplary embodiment of the present invention, a fat removal tool for removing fat from the outer surface of an internal body organ comprises a screen having at least one passageway sized to allow fat cells to extrude through the screen while preventing a blood vessel selected from the group consisting of a patient""s coronary arteries, a patient""s cardiac veins, and both, from passing through said screen, and a separate cutting member positionable adjacent to said screen to cut fat which has been extruded through said screen passageway.
In accordance with a seventh exemplary embodiment of the present invention, a fat removal tool for removing fat from the outer surface of an internal body organ comprises a handle having a proximal end, a distal end, and a hollow interior, a screen at said handle distal end, said screen including at least one passage therethrough, a rotatable blade in said handle and immediately proximal of said screen, and a rotatable shaft attached to said blade and extending proximally from said rotatable blade.
In accordance with an eighth exemplary embodiment of the present invention, a fat removal tool for removing fat from the outer surface of an internal body organ comprises a screen having at least one passageway sized to allow fat cells to extrude through the screen while preventing a blood vessel selected from the group consisting of a patient""s coronary arteries, a patient""s cardiac veins, and both, from passing through said screen, and a cutting member adjacent to said screen and movable over said screen to cut fat which has been extruded through said screen passageway.
In accordance with a ninth exemplary embodiment of the present invention, a method of removing a fat layer from the surface of an internal body organ comprises the steps of exposing a portion of said fat layer, pressing said fat layer with a surface having at least one hole, extruding fat through said at least one hole, and cutting said fat that has extruded through said hole on a side of said surface opposite said fat layer.
In accordance with a tenth exemplary embodiment of the present invention, a method of removing a fat layer from the surface of an internal body organ comprises the steps of exposing a portion of said fat layer, pressing said fat layer with a surface which vibrates at a frequency and magnitude sufficient to rupture cell walls contained in said fat layer, and aspirating fatty tissue.
In accordance with an eleventh exemplary embodiment of the present invention, a fat removal tool comprises two bipolar wires each having a cross-sectional diameter and a centerline, each bipolar wire having a cross-sectional diameter from about 0.150 inches to about 0.045 inches, the two bipolar wires spaced from each other at a centerline-to-centerline distance from about 0.040 inches to about 0.200 inches.
In accordance with a twelfth exemplary embodiment of the present invention, a fat removal tool comprises a first outer sheath electrode having a lumen and a distal end, the outer sheath electrode including holes at the distal end to allow fat to enter the lumen, and a second helical wireform inner rotatable electrode positioned in the lumen to rotate relative to the holes to move to the proximal end of the tool any fat that is melted upon application of radio frequency energy between the first and second electrodes. such that a vacuum source can remove the fat from the tool.
Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings.